A method and apparatus for discovering and configuring peripheral devices on a network, notifying potential users of the presence of a peripheral device on a network, and conveniently configuring a workstation to use peripheral devices.
Peripheral devices allow users to put information into or get information out of a computer system. Peripheral devices include, but are not limited to, printers, scanners, copiers, and facsimile machines. Earlier generations of peripheral devices performed a single function and had a limited ability to communicate with other devices or process information. Many peripheral devices today, however, are able to perform multiple functions and are capable of sophisticated communications and information processing. A multifunction peripheral (“MFP”) is a peripheral device that can perform the functions of more than one traditional peripheral device. For example, a single device that can perform the functions of a printer, scanner, copier, and facsimile machine is an MFP. An intelligent peripheral device (“IPD”) is a peripheral device that includes an embedded microprocessor and memory for controlling its operation or for performing other tasks, such as communicating over a network with workstations, server computers, and other peripheral devices. An IPD can sometimes perform the functions of a server and is typically also an MFP.
A typical network (“network”) includes a plurality of computer systems and peripheral devices capable of communicating with each other. A network can be a local area network, a wide area network, a plurality of networks, wireless networks, or other type of network. The computer system used by an individual user in a network environment is typically referred to as a “workstation.” Other computer systems on a network perform various network services and are referred to as “server computers.” The software associated with the computer systems and peripheral devices on a network includes clients and servers. A client is a program (a “process”) that sends a message to a server requesting that the server perform a task (a “service”). A server is a process that performs the requested task. While a client and a server may run on the same computer system, the client usually runs on a workstation while the server runs on a server computer dedicated to performing one or more server processes. In addition, a network generally includes a server computer that runs a network operating system, which in turn, provides various network services necessary for managing the network. For example, a network operating system often includes a file server, a print server, e-mail, and a directory server.
A hyperlink or hot link (“link”) is a connection between two hypertext objects and generally appears in a document as a highlighted word, phrase, or graphic object. In operation, clicking on a link causes the target object to be displayed. The target object can be a point elsewhere in the document, a Web page, or a service on a server computer. Hypertext transfer protocol (“HTTP”) is a widely used protocol for transferring a target object from a server to a client.
When a new peripheral device is physically connected to a network, performing a software setup process is necessary before other devices on the network can communicate with the peripheral device. The setup process involves configuring various network settings, such as Internet protocol (“IP”) addresses, Lightweight Directory Access Protocol (“LDAP”) server entries, network masks, domain name system (“DNS”), and other similar network settings. After network settings for the peripheral device have been established, the workstations of users who want to use the peripheral device must be configured. This requires identifying potential users of the new peripheral device and installing device drivers on their workstations. For example, when a new printer is connected to a network, network settings for the printer must be configured and a print queue must be established on a print server. Users must be told the names of the print server and print queue and must install device drivers for the peripheral device. To install a device driver, the user typically navigates to the correct server through a directory tree displayed on his workstation, locates the correct print queue, and then double-clicks on the queue name. Similarly, when a new device (e.g. a scanner) is attached to a network, network settings for the device must be configured, and the workstations of users wanting to use the scanner generally must register with a scanner server. In order to register with the scanner server, the user must be made aware of the scanner, its IP address, and the required setup process.
While networks can be small, consisting of a few workstations sharing a single peripheral device, they are typically much larger, often comprising hundreds or even thousands of workstations and peripheral devices. But users generally want to be able to use only the services of peripheral devices that are near their workstations. Networks are complicated by their dynamic nature, with workstations and peripheral devices being frequently added and removed, and by the frequent release of new versions of software (such as device drivers) that must be installed on server computers and workstations. In addition, when a peripheral device is assigned a new IP address, subnet mask, gateway, or DNS server, the setup configuration of the workstations with which the device communicates must be updated.
The size and dynamic nature of many networks make it difficult for systems administrators to set up and maintain workstations so that users are able to use nearby peripheral devices. This task could be left to the user, but proper setup and maintenance of workstation configurations requires some level of expertise. The user must be able to navigate through an often complex series of steps to locate and install the software necessary to communicate with the peripheral device. Another problem is that many users, even if technically sophisticated, are unwilling to perform these steps because they are time-consuming. Users want to be able to use a peripheral device in a simple and transparent manner. If the setup process is complex or time-consuming or doesn't go smoothly, a time-pressed user will simply abandon the attempt to set up the peripheral device. Moreover, the user needs to be informed each time a peripheral device is added to or removed from the network. And finally, the user needs to be informed each time a new version of software required to use a peripheral device is released.
To simplify and standardize the setup and maintenance process, several protocols have been developed that coordinate the configuration of computer systems and peripheral devices on a network (“configuration protocols”). Prominent configuration protocols that have been proposed or are in use today include Service Location Protocol (“SLP”); Jini; Universal Plug and Play (“UPnP”); and Universal Description, Discovery, and Integration (“UDDI”).
SLP is an Internet Engineering Task Force (“IETF”) standard that provides a framework for network-based applications to discover the location of a service. SLP requires a Directory Agent, a Service Agent, and a User Agent. The Directory Agent stores information about services available on the network, including their network addresses. A Service Agent advertises a service. A User Agent discovers services for its client. In operation, Service Agents register with the Directory Agent, and a User Agent that wants to use a service contacts the Directory Agent. Service and User Agents learn the location of the Directory Agents in several ways. First, Service and User Agents can multicast a request to the network, and a Directory Agent that hears the request can reply. Second, a Directory Agent can multicast an advertisement of its location to the network. Third, Service and User Agents learn the location of the Directory Agent using Dynamic Host Configuration Protocol (“DHCP”). If there is no Directory Agent on the network, a User Agent that wants to use a service broadcasts its request to the network repeatedly; a Service Agent capable of providing the requested service will respond and fulfill the request. A drawback of SLP is that it requires that the described Agents be running on the network. A further drawback of SLP is that only network-based applications are able to discover the locations of services.
Sun Microsystems' Jini architecture is similar to SLP, but it is based on the Java language and is object-oriented. When a peripheral device is attached to a network, it broadcasts a message to the network requesting that all Lookup Services on the network identify themselves. The peripheral device then registers with responding Lookup Services. A workstation that wants to use a service locates one by sending a list of desired attributes to the Lookup Service. In response, the Lookup Service sends the workstation an object for a service that satisfies the requested criteria. The workstation uses the object to request the service from the peripheral device. A drawback of Jini is that it generally requires that a Lookup Service be running on the network.
UPnP is a framework for the configuration of network devices that is defined at the network transport layer (transmission control protocol (“TCP”)/IP layer). UPnP requires that device manufacturers build application program interfaces (“APIs”) for their devices that implement UPnP protocols. When a device capable of controlling other devices is attached to a network, it broadcasts a message to the network requesting that all devices on the network announce their presence. When a device that only provides a service is attached to the network, it sends an advertisement of its presence to the network. While UPnP provides the protocol support for configuring devices on a network, a drawback of UPnP is that it doesn't provide a simple method for a user to configure network devices. To set up and maintain workstations so that they are configured to use the services of nearby peripheral devices, UPnP requires software at the network application layer.
Examples of patent references directed to configuring workstations to use the services of nearby peripheral devices are given below.
U.S. Pat. No. 5,960,167 to Roberts et al. (the “Roberts reference”) discloses a method for configuring a printer on a network and enabling workstations to use the printer. When a new printer is added to the network, it broadcasts an advertisement to the network. The advertisement is stored in a table, which an auto-install utility periodically reads to see whether new printers have been added to the network. If the auto-install utility discovers a new printer, it configures the printer and creates a print queue, a print server, a printer object, and a printer agent. The Roberts reference is limited in that it requires the auto-install utility to be run on a periodic basis; it also requires a print service manager and service registry service. These requirements add considerable overhead and complexity to a network. Further, the Roberts reference requires a server computer to run a shared printer driver.
U.S. Pat. No. 5,692,111 to Marbry et al. (the “Marbry reference”) discloses a method that permits a user to print to a printer on a network even if that printer's configuration information and printer driver are not installed on the user's workstation. Printer-configuration information and printer drivers are stored on a network server. The user identifies a network printer when requesting a print job or running a printer-installation wizard. Configuration information and a printer driver are copied from the network server to the user's workstation. A drawback of the Marbry reference is that the user must know the location of the server and print queue to configure a printer. To learn the location of the server and print queue, the user must search through a directory structure. This process can be burdensome and confusing because the user may have to search through hundreds of printers hidden in dozens of folders that are given arcane, technically oriented names assigned by a system administrator. A further limitation of the Marbry reference is that the user is not made aware of nearby printers that are newly attached to the network.